1. Field of the Invention
The present invention relates to a high-pressure regulating valve. More particularly, the present invention relates to high-pressure regulating valve configured with a radially oriented opening in the valve body and improved performance.
2. Description of the Related Art
The high-pressure regulating of fluids occurs generally by means of ball-seat valves. These are as a rule electromagnetically actuated. Electromagnetically operated high-pressure regulating valves of the prior art are generally built as follows, an example is depicted in FIG. 3.
The valve 1 has a valve body 2 with an inlet 20 and an outlet 21, in which pressures up to 2400 bar can occur at present at the inlet side or in the area of application of the common-rail motors. Between the inlet 20 and the outlet 21 there is disposed a valve seat 3, through which passes a valve bore 30, connecting the inlet 20 and outlet 21. The valve bore 30 can be sealed off at the outlet end by a sealing means 4, which is generally designed as a sealing ball. The sealing ball 4 can be pressed against the valve seat 3 by a valve pin 5 for this purpose. On account of the increased loads acting through the sealing ball 4, the valve seat 3 is made of hardened steel. For cost considerations, the rest of the valve body 2 is made of unhardened steel.
The valve seat 3 is disposed on the valve body 2 such that it connects the inlet end and the outlet end. The valve seat 3 is basically configured as a plate at the outlet end and has a recess in the area of the valve bore 30, in which the sealing ball 4 comes to lie. At the inlet end, it is press-fitted into the valve body 2.
The outlet 21 is formed by radial bores 23 at the outlet side of the valve body 2. To achieve the most compact possible form of the high-pressure regulating valve 1, the radial bores are disposed as closely as possible beneath the valve seat 3. Thanks to this design, a shoulder 22 is formed between the valve seat 3 and the outlet bores 23, against which the valve seat 3 is braced while screwing the valve together.
The valve pin 5 is mounted in a lengthwise bore of the valve body 2 and can be moved along its longitudinal axis by an electromagnetic drive unit 6, disposed at the outlet end. The drive unit 6 is not shown at present. It is generally constructed from a coil 61 through which current can be passed, disposed on a coil holder 60, and an armature 62 that can be actuated by a generated magnetic field. The armature 62 and the valve pin 5 are welded or press-fitted together and thus permanently joined to each other. The armature 62, furthermore, is biased by a compression spring 68 in the closing direction of the valve, so that the valve 1 is closed when no current is passing through the coil 61.
The armature 62 and the compression spring 68 are mounted at the rear in a bushing 65, which is fastened to the valve body or by a welded ring 66. The valve pin 5 is held centered in the bushing 65 by a bearing 69.
The regulating of the flow of fluid occurs by the lifting off of the sealing ball 4 from the valve seat 3. In the present high-pressure regulating valves 1, the maximum lift, i.e., the lift achieved at maximum opening of the valve, is 0.2-0.5 mm. Upon opening of the valve, due to the pressure acting on the sealing ball 4 from the inlet side, very high flow velocities of the regulated fluid are reached. The fluid then impinges with this high flow velocity against the shoulder 22 of the valve body 2 at the outlet end and erodes it, i.e., in the course of the lifetime of the valve increasingly more material of the shoulder 22 is ablated, so that its material thickness is attenuated.
An attenuation of the valve body 2 in this area implies serious drawbacks in regard to the lifetime of the valve, since with increasing erosion less force can be transmitted from the screw connection via the valve seat 3 to the valve body 2, so that the valve ultimately loses its tightness in the area of the press fitting.
A further drawback of erosion is the subsequent ablation of material. Particles of the ablated material can get into the fuel system and thus, for example, lead to damaging of the high-pressure pump of the fuel system.
The problem of the present invention is to provide a high-pressure regulating valve that does not have at least one of the above-mentioned concerns. Accordingly, there is a need for a high-pressure regulating valve that overcomes one of the concerns noted above.